Pathological fracture

Question 1

What is a pathological fracture?

Answer 1

A spontaneous fracture following mild physical exertion or minor trauma due to abnormal weakness of the bone that is caused by an underlying condition.
- Common Locations ⇒ spine, hip and wrist

Question 2

What are some causes of a pathological fracture?

Answer 2

1. Disorders affecting bone metabolism → osteoporosis, paget disease, osteopetrosis, osteomalacia, osteogenesis imperfecta
2. Masses → malignant bone tumours (osteosarcoma, chondrosarcoma, Ewing’s tumour), bone metastases (prostate, breast, lung, thyroid, renal), benign bone tumours, multiple myeloma

Question 3

What are the presenting symptoms of a pathological fracture?

Answer 3

• Pain
• B symptoms ( systemic symptoms of fever, night sweats, and weight loss)
• Symptoms specific to cancer
• Hypercalcaemia of malignancy symptoms

Question 4

What investigations are used to diagnose/ monitor a pathological fracture?

Answer 4

1. Paget Disease → isolated ALP elevation. Normal calcium, phosphate and PTH levels. Tx with bisphosphonates.
   - Most commonly affected bones are the pelvis, vertebrae, skull, femur and tibia.
   - Typical presentation = older male with bone pain
2. Malignant Bone Tumours → plain radiograph as initial test. Biopsy to confirm radiologic diagnosis.
3. Bone Metastases → hypercalcaemia + raised ALP 
4. X-Ray:
   - Sclerotic Lesions ⇒ metastatic prostate cancer
   - Osteolytic Lesions ⇒ metastatic kidney/thyroid/lung cancer, multiple myeloma, paget’s disease

Question 5

How are pathological fractures managed?

Answer 5

Treatment generally involve operative fixation combined with chemotherapy and/or radiotherapy. 
1. Upper extremity: 
- The humeral head and anatomic neck of the humerus: shoulder hemiarthroplasty versus total shoulder arthroplasty versus reverse total shoulder arthroplasty versus endoprosthesis versus fixed-angle plate with void filler 
- The surgical neck of the humerus to the proximal-third humeral shaft: fixed-angle locking plate 
- Humeral diaphysis: locked antegrade intramedullary nails versus plate 
- Distal humerus (less common): parallel bridge plating versus distal humeral replacement with total elbow arthroplasty 
- Radius/ulna (uncommon): plating versus excision 
2. Lower Extremity 
- Femoral head and neck: hemiarthroplasty versus total hip arthroplasty versus endoprosthesis versus plate or nail fixation with void filler 
- Intertrochanteric, subtrochanteric, diaphyseal fractures: cephalomedullary nails 
- Distal third femoral shaft: locking plate versus retrograde intramedullary nail (a musculoskeletal oncologist must carefully consider any retrograde nailing before proceeding to avoid proximal tumor spread) 
- Supracondylar: distal femur periarticular plate 
- Proximal tibia: locking plate versus endoprosthesis 
- Tibial shaft: intramedullary nail  

Question 6

What are complications may arise following a pathological fracture?

Answer 6

• Failure of fixation
• Infected hardware
• VTE
• Poor mobility  

Question 7

Describe the prognosis of a pathological fracture?

Answer 7

The survival rates for the metastatic bone disease are determined by the primary malignancy.